Do you have issues with SPD? Why did you change? In my case, it was the float and knee issue that made me move to Speed Play. As for stiffness, that is in your shoes. (try S-works MTB shoes then S-works Road one I would be surprised if you can tell difference... - I do have both). One thing is road pedal tend to have better platform (which you can get SPD pedal with bigger platform as well) If SPD or another MTB pedal has more adjust-ability than speedplay, I would be all over it myself as I already have 4 different MTB shoes (3 sneakers, 1 S-works) I can use as well as making it easier for me to walk...